No Difference in Postoperative Knee Flexion and Patient Joint Awareness Between Cruciate-Substituting and Cruciate-Retaining Medial Pivot Total Knee Prostheses: A 10-Year Follow-Up Study.

Abstract

This study aimed to clarify differences in clinical results, including in patients' joint awareness, between cruciate-substituting (CS) and cruciate-retaining (CR) medial pivot total knee arthroplasty (TKA) over a 10-year follow-up. A total of 333 TKAs were included in this study. There were 257 cases of CS and 76 cases of CR TKAs. Knee range of motion, Knee Society Score, and radiological outcomes were assessed. The patients' joint awareness was evaluated using the Forgotten Joint Score-12 at the final follow-up. The survival rate with respect to reoperation or revision was analyzed. The mean follow-up period was 10 ± 1.7 years, and the loss to follow-up was 5.4%. All clinical outcomes improved significantly after surgery in both groups (P < .001). Postoperative knee flexion was 118° ± 13° in the CS group and 116° ± 10° in the CR group (P= .10). The mean Forgotten Joint Score-12 scores were 57 ± 27 points in the CS group and 56 ± 28 points in the CR group (P= .59). Ten years after the operation, the survival rates for reoperation were 96.3% in the CS group and 94.2% in the CR group (P= .61), and those for revision were 98.4% and 98.7% in the CS and CR groups, respectively (P= .87). Other postoperative clinical results did not differ between the 2 groups. In this 10-year follow-up study, medial pivot TKA, regardless of polyethylene insert type, showed a high survival rate and good patient awareness of the prosthetic joint.